Radiator



Jan. 2, 1934. J. ASKIN 1,942,380

RADIATOR Filed Jan; 24, 1933' 2 Sheets-Sheet 1 Zhwentor JQSEPH AsKlN Gttorneg Jan. 2, 1934.

J. ASKIN l.942,380

RADIATOR Filed Jan. 24, 1933 2 Sheets-Sheet 2 FIG.4. 5o

Zhwentor JOSEPH AsKm (Zttomeg Patented Jan. 2, 1934 UNITED STATES PATENT OFFICE RADIATOR Application January 24, 1933. Serial No. 653,273

2 Claims.

This invention relates to cellular radiator cores, and it has particular reference to a deep core which is so constructed as to have a maximum thermal efliciency and high mechanical strength.

In the art of making cores for automobile radiators, it has been common practice to make what is known as a cellular core, formed from strips of metal which are joined at their mar- 0 gins to serve as water passages, between which are interposed other strips of metal serving as spacers and providing passages for circulation of air to cool the water flowing in the water courses. These cores are made by assembling the strips for the water passages and spacers in a suitable clamping frame, and then immersing the core while horizontally disposed to a depth of about an eighth of an inch from each face in a bath of molten solder, to secure the parts to each other. The characteristics desired in the completed core are a high rate of heat transfer between the water and circulating air, ability to reduce the water temperature to a certain low value, strength to withstand the effects of strains imposed on the core during service, and concomitantly with these effects, low weight and facility of manufacture.

I have found that the thermal efiiciency or heat transfer capacity of such cores varies with the extent of union or bonding between the water passages and spacers. Thus, there is frequently a difference of as much as fifteen per cent in efficiency, between a well dipped or soldered core and one which is poorly or carelessly soldered. Since the area of contact between the water passages and spacers is necessarily limited, in view of the requirement of air circulation, it is therefore desirable to efi'ect the greatest possible degree of soldering or bonding at such contacting portions as are available, in order to obtain the maximum eificiency for a given weight of metal.

For a better understanding of the principles of my invention, I may here explain the manner in which I believe good soldering is obtained, by the dipping method referred to above. As stated, the cores are dipped to a very limited percentage of their depth, first on one side, and then on the other. If a proper time of immersion is provided, and the core parts are carefully aligned in the clamping frame, the solder creeps or flows along the lines of contact between spacers and water lines, considerably above the actual plane of immersion. This upward flow of molten solder into the interstices between the contacting ribbons may be explained on the theory of capillary action, the fine spaces between such parts serving as wicks or capillary tubes. In well conducted practice, solder bonds may be obtained to a height of two inches or slightly more above the actual plane of core immersion, as measured from the sidefirst immersed.

To this point, reference has may be called shallow" been made to what cores, or those which are less than or not much more than three inches in depth. When cores of this or greater thickness are assembled, by the same process, it is found that the solder does not extend inwardly along the lines of contact to the same extent, and does not extend inwardly from opposite faces to the same amount. Hence the beneficial effects sought for from the solder bonds are not obtained, and the core is not only structurally weak, but is lacking in thermal effectiveness. This ap pears to be paradoxical, on the premise that capillary action is a factor in causing the solder to flow, as it could be further premised that a core of say four inches in depth could be completely bonded by immersing first on one side, and then on the other, to draw the solder inwardly about two inches from each side. Such flowing of solder is not obtained, however, in deep cores, or those which have a thickness'appreciably in excess of the range of capillary penetration from one side, and it may also be noted that such bonding as is obtained is irregular and lacking in uniformity.

The present invention seeks to improve existing structures by providing a cellular core particularly adapted to be made as a deep core, and which may, despite the foregoing stated phenom- 0 ena, be uniformly and completely bonded along the lines of contact by the usual dipping operations. Additionally, the core of the present invention is made with a. high degree of strength, thermal efliciency, and ability to reduce the hot water to a proper low temperature, without proportionate increase in weight. These results are primarily obtained by making a deep core with a continuous central rib or relieved portion in the water passages, and providing for continuous contact between the water passages and the spacers except in the vicinity of the rib. By this means, resistance to the equal capillary fiow of solder from both faces of the core is removed, and the core itself is strengthened to withstand distorting forces which are set up during the soldering operation, or in subsequent use.

A core illustrating the principles of the invention is shown in the accompanying drawings,

wherein:

Fig. 6 is a transverse section of an assembled core, showing the lines of contact and spacing between the inner and outer ribbons.

Figs. 1, 2, and 3 illustrate the components of the core, as they appear during the course of manufacture and prior to assembly. The ribbon shown in Fig. 1 consists of a pair of similar strips of sheet metal 11 and 12, each of which is formed in a generally zig-zag fashion to provide projecting crests 13 and receding troughs 14. Each ribbon is offset at its margins above the general line of convolution, and the midportion of the ribbon is similarly offset to provide a continuous rib or offset portion 16, the several purposes of which will be discussed more fully hereinbelow. It willbe noted, however, that the offset portion 16 is of narrow width, compared with the distance between the portion 16 and the marginal portions 15, and that the troughs 1d are formed with plane faces to provide areas, instead of fine lines of contact. The crests 13, however, may be pointed, as they are notintended to contact with other portions of the core.

A pair of such ribbons may be united at their ends, as shown in Fig. 1 by the numeral 1'7. to form an outer" ribbon unit, composed of adjacent elements of adjacent water passages in the core. These elements are held in spaced relation by the inner ribbon, or spacer, one suitable form of which is shown in Figs. 2 and 3,, and which is indicated only diagrammatically in 1 by the numeral 21, to avoid too much detail.

The spacing ribbon 21 is formed in a generally zig-zag conformatiomwith projecting crests 22 and receding troughs 23. The marginal portions of the spacer 21 are elevated'above the mid portion thereof, and the projecting crests 22, intermediate the marginal portions, are flattened slightly to form contact areas 24 adapted to abut the contact areas of the troughs 14 of the water passages. The spacing ribbon is deformed intermediate the marginal portions with a plurality of alternately depressed and elevated knobs 25 projecting above the passages defining the crests and troughs, to serve the purposes of interlocking the assembled elements and increasing the air turbulence during service. These spacing ribbons are adapted to be folded, as shown in Fig. 3, with the troughs 23 abutting each other and bein interlocked by the knobs 25, and with the crests 22 projecting outward on each side of the unit. When out to suitable length, an inner ribbon may be interted between a pair of assembled outer ribbons, with the flat troughs of the water passages contacting the flat crests of the spacer, as illustrated in Fig. 1 and also in Fig. 6. A number of such units may then be assembled in a frame, for dipping to form a complete core.

. AsshowninFig.6,anda1soinFigs.4and5,

upon assembly of a number of units of inner and outer elements, the outer ribbons contact along their marginal portions 15, and also contact or tend to contact along their central oifset portions resaseo as indicated by the numeral 15,

16, but intermediate such portions, the ribbons 1E and 12 are mm spaced to provide a water passage 26. Both portions of the water passage, ne ribbons ii and 13, are in continuous contact with the spacing ribbon 21. along the abutting areas 14 and 24, but such continuous contact is interrupted along the midportion of the core at the portions 16. The enveloping walls of the water passages and spacers at these points define vertical passages or fines 27, through which air may escape by" upward or downward flow, so that an increased degree of turbulence is obtained than would be the case if the air could flow only horizontally through the core. Thus. referring to Fig. 4, it will be seen that the spacer ribbon 21 divides the space between adjacent water passages into horizontal pockets 31 and 33, respectively contiguous with the water passages, and central pockets 32 extending between the water passages. Each pocket 31 or 33 is in communication with the other pockets 31 or 33 through the vertical flue 27 formed around the centralelement 16, and hence the heat transfer to the volumes of air flowing through such pockets may be equalized to obtain-increased total heat exchange. It may also be pointed out that each of the air pockets is defined in part by the metal of the water passages, or by metal soldered thereto, and hence a rapid heat transferrence may be had from the water flowing in the tubes 26 to the material of the spacers, and the air passing therethrough.

It has been stated hereinabove that, to obtain maximum heat transfer capacity per unit of weight, good thermal contact between water pas sages and spacers is essential- The foregoing core construction has been particularly devised to obtain such contact. In Fig. 5, it may be assumed that the distance irom either face of the core to the central flue 27 is somewhat less than the normal .capillary lift of the solder, and hence, when the core is dipped, to a depth of about the width of the marginal portions 15, the solder will run upwardly and form a continuous bond along the contacting edges 14 and 24. This result can be obtained, provided the parts are properly made, and there are no distorted portions along such contacting areas, which would separate the water ribbons and the spacers to any appreciable extent. If there is appreciable deformation in 35,25.

the core parts, the space therebetween will be so great that capillary force will not elevate the solder'to the height desired. By providing the. continuous central rib 16, the metal of the water passage is somewhat reinforced and is enabled to hold its shape under the compressive load of the clamping frame. The central rib 16 thereby insures the proper close contact during the assembling operation, without increase in the weight of the core. 1

When the core is reversed for dipping on the, opposite face, thecentral flue 27 serves an additional purpose, to overcome the resistance to solder flow in deep cores, as described above. If the central flue 2'1 were omitted, the capillary o tubes, after dipping-on one side, would be sealed oil, and the air entrapped within such tubes would prevent the solder from flowing upwardly under the capillary attraction, to form a continuous bond. Or, as also may happen in practlce, the air so entrapped becomes heated from 7 the molten solder and expands between the contacting areas 14 and 24, thereby spacing them so greatly that the feed of molten metal is interrupted. By providing the central flue 2'7, a means of escape for such air is provided, the heated air moving upwardly ahead of the solder into the flue 27 and thence out of the core through the pockets 21 and 32. At the same time, any tendency toward distortion of the light metal of the ribbons is counteracted by the strength imparted by the central rib 16.

It will now be seen that, by this invention, there is provided a core which is adapted to be made in deep sections, but in which provision is made for insuring the maximum possible bonded contact between water passage and spacing ribbons. Not only does the described structure lend itself to accurate manufacture, whereby a predetermined high thermal efliciency may be obtained, but the core, when made, is possessed of high strength and increased heat transfer properties, without proportionate increase in the weight of metal.

While I have described my invention with reference to my observations and discoveries on the action of solder during a dipping operation, in order that the principles and advantages of such invention may be understood and applied by others skilled in the art, it will be appreciated that the results obtained exist apart from the ultimate correctness of matters of theory, and that I regard as my invention a radiator core, as defined by the following claims.

I claim:

1. A cellular core for radiators comprising a plurality of imperforate ribbons joined to each other along their margins and spaced from each other intermediate said margins to form water passages, said ribbons being formed into a zig-zag conformation having alternate crests and mood-- ing portions, the marginal portions of said ribbons being elevated above said intermediate portions, a central offset portion in said intermediate portion, said oifset portion also being elevated above said crests and being continuous throughout the length of said ribbons, and spacer ribbons interposed-between adjacent water passage ribbons to space the same, said spacer ribbons being formed in zig-zag conformation and being provided with crests adapted to contact alternate projecting portions of adjacent water ribbons, said contact being continuous from said marginal portions to said central offset portion, said contact being interrupted at said central portion to form vertical flues.

2. A deep core radiator comprising a plurality of juxtaposed and interconnected water passages and spacer ribbons, each of said water passages being formed of a pair of imperforate ribbons of zig-zag conformation joined to each other along their margins and mutually spaced along their intermediate portion to form water passages, a continuous offset portion formed along the center of each water ribbon, projecting flat faces on each side of said water ribbon, said spacer ribbons being formed in zig-zag conformation provided with flat projecting portions adapted to contact the fiat projecting portions of said water ribbons from the marginal portions thereof to said offset portion, the portions of said offset portion and said spacer ribbons adjacent said ofl-set portion forming a vertical flue, the said vertical flue being located inwardly from either face of said ribbon a distance such that molten solder may rise in said contacting flat portions to said flue when said core is partially immersed in a solder bath.

JOSEPH ASKIN. 

